1. Field of the Invention
This invention relates to an opening device for detaching fiber tufts from compressed fiber bales such as cotton or cellulose fiber bales or the like. The opening device has rapidly rotating opening (detaching) rolls which have toothed discs or spikes that cooperate with a grate whose grate bars are situated between the detaching discs or spikes. The opening device travels along the top face of the stationary fiber bales and detaches fiber tufts therefrom.
2. Description of the Related Art
In a known opening device the parallel axes of the opening rolls are in a horizontal alignment with one another. During the forward and return pass the opening rolls penetrate the upper surface of the fiber bale to an equal depth during the detaching operation. The opening rolls rotate in opposite directions such that in the zone of the fiber bales the circumferential part of the opening rolls move towards one another. It is a disadvantage of these constructions that as the detaching rolls travel in a given direction during the detaching operation, the two opening rolls detach different quantities of fiber tufts from the fiber bales (one opening roll rotates in the direction of travel and the other rotates oppositely thereto).
In the parent application Ser. No. 07/387,992 as well as in U.S. Pat. No. 4,928,354 (issued May 29, 1991) a pivotal height adjustment of the two opening rolls is provided; the rolls, however, are pivoted in a vertical plane as a unit, that is, no individual pivotal adjustment is feasible.
United Kingdom Patent No. 946,333 discloses a fiber bale opening apparatus having a series of parallel-arranged opening rolls and further wherein the fiber bales are conveyed underneath the opening rolls. Each opening roll is individually vertically linearly adjustable. As viewed in the direction of relative displacement of the rolls with respect to the fiber bales, during operation each roll is at a higher level than the roll which trails it.